The present invention relates to a biopsy syringe device for removing a biopsy specimen from a subject, and also to a method of using such a device.
A biopsy is a surgical procedure for removing a small sample of tissue from a person for the purpose of examining it under a microscope to see whether a disease is present. One common technique for performing a biopsy, particularly where the specimen to be removed is from the liver or kidney, is to use a biopsy syringe having a long hollow needle which is passed through the abdominal wall.
In using the conventional biopsy syringe for this purpose, the syringe is filled with about 3 cc saline before the hollow needle is passed through the abdominal wall. When the hollow needle has passed through the abdominal muscles and has entered the abdominal cavity surrounding the organ from which the specimen is to be removed (this being felt by the physician by the drop in force required to force the needle through the abdominal wall), about 2 cc of the saline are ejected through the hollow needle, and into the abdominal cavity in order to clean the needle of the tissue accumulated therein during its passage through the abdominal wall; the piston is then pulled back to a retracted position to create a vacuum therein; and the needle is then further pushed into the organ (e.g., liver, kidney, etc.) from which the specimen is to be taken, which specimen fills the interior of the hollow needle. The hollow needle is then withdrawn from the subject, and the remaining 1 cc saline water is used to expel the sample.
One serious drawback in the use of the conventional biopsy syringe for removing specimens in this manner is the difficulty for the physician to determine exactly when the needle has passed through the abdominal wall and into the abdominal cavity but has not yet entered the organ from which the biopsy specimen is to be removed. Thus, if the saline is ejected too soon, it will be injected into the muscle, such that subsequent uptake of the tissue sample will be of muscle tissue and not of the organ of choice; and if ejected too late, the saline may be injected into the organ itself which could cause damage. Another serious drawback is the difficulty for the physician to hold the device steady, particularly when moving the plunger rod in one direction to eject the 2 cc of saline after penetrating the abdominal muscles, and then moving the plunger rod in the reverse direction to create the vacuum, both movements being effected before entering the organ from which the specimen is to be taken. Thus, any slight lateral movement of the device at this critical time can cause considerable lateral movement of the needle tip within the organ which could result in considerable damage to the organ, accompanied by extensive internal bleeding due to the fact that the internal organs such as the liver, kidneys, etc., are soft tissues with a very extensive blood supply.